Several hundred thousand people in the USA each year require artificial blood vessels, "grafts", to be placed in their legs because of failing circulation. Sixty thousand of these patients require artificial prosthetic grafts. Unfortunately, many of the artificial grafts become occluded in just a few years (almost 40 % fail within a year), leading to leg amputation. The overall goal of this program is to improve the lives of people requiring artificial vascular grafts by decreasing the need for amputation. In addition to improving quality of life, there will be a substantial reduction in cost to the medical system. In earlier phases of this SBIR program, a "smart graft" was successfully developed and tested;a smart graft not only carries blood, but also measures the blood flow and, by means of an implanted transceiver, wirelessly transmits these measurements to a base station outside the body. The base station alerts a physician to an impending graft occlusion if the smart graft's measurements show impending occlusion. The purpose of this Renewal proposal is to bring the development of the smart graft to the point of readiness for human trials, the last step before commercialization To do so, the smart graft will be enhanced by adding pressure measuring to flow measuring, improving the validity of its measurements. (It also allows doubling the battery-life). The improved smart grafts will be implanted in dogs along with a controllable stenosis, already developed for this program. By monitoring the flow and pressure in the graft as the stenosis is increased causing the graft to occlude, the changes in flow and pressure that show impending graft failure can be determined. These signs of imminent graft failure will be validated in the final part of the program in which smart graft life in one leg of a dog will be compared with the survival of a conventional graft in the other leg. The trial is designed to show that smart grafts will significantly increase graft life and therefore reduce amputations. In addition, the trial will demonstrate the safety of the smart graft, i.e. its biocompatibility and lack of side effects. With proof of graft efficacy and safety, human trials of smart grafts will be able to begin. Smart grafts will lead to far fewer amputations, both improving care and also reducing costs. PUBLIC HEALTH RELEVANCE: The artificial grafts needed to correct poor circulation in the legs frequently become occluded, which leads to amputation of the legs. We have developed a new graft that alerts the physician that the graft is occluding to allow timely intervention, and thus prevents graft failure. Reducing the number of amputations both improves quality of life and reduces costs.